I'm flying a Eachine 250 Racer with APM 3.1 Mini, Orange R615X Receiver, and Bluetooth Module. I've had several good autonomous missions, but noticed that sometimes while in Auto mode, the mode changes from Auto to Land and then back to Auto without any RC input from my transmitter. Sometimes it switches into Stabilize mode by itself then back to Auto. In some cases, I've had crashes too. I have set APM failsafe to RTL and it works great on the bench. My missions are never more than 300 feet from the launch point.
The receiver is set for CPPM with Throttle on Ch3 and Flight Modes on Ch5 I use the Aux (Ch 6) in PWM mode to control the LEDs.
Based on a cursory look at my flight log, I'm thinking it is random false input from the receiver, but don't know enough about it to tell for sure. Interestingly enough, Ch6 shows similar random RC input changes in sync with Ch 5 even though I don't toggle the LEDs during the flight. Same with Throttle; the log shows RC input changes, but I keep it at midpoint. Manual flights seem to be ok.
Could anyone please tell me what is going on? I'd greatly appreciate any input.